The present invention relates to a paper container of heat-sealable coated surface-protected cardboard which includes a wound container wall and of a container bottom connected therewith. The ends of the container wall blank are overlapped and the end disposed on the container inside is folded over toward the outside for covering off the inner cut edge. The present invention also relates to a method for the manufacture of such a container.
Paper containers of the aforementioned type are generally known in the prior art (see for example German Offenlegungsschrift 30 23 835), such containers customarily being filled with liquid, for example, with fruit juices. The surface coating in this prior art device extends only over the outer wall surfaces so that, if no special measures are taken, the exposed inner cut edge is unprotected as a result of the overlap of the ends of the outer container wall. This cutting edge is permeable by the liquid container content so that the liquid contained therein can penetrate into the paper and soften the same. For purposes of avoiding this disadvantage, provision is made in prior art paper containers to scrape off or abrade the end strip which is on the inside after the winding operation, essentially to half the material strength over a predetermined width. The abraded area is subsequently folded in such a manner that the end surface of the abraded area and the end surface of a non-abraded area of the blank contact one another. The container wall structured in this manner results in a container having a constant wall thickness. Subsequent to the folding over the abraded end strip, the end surface of the blank is then provided with a waterproof coating. The otherwise exposed inner cut edge is thus covered off.
The exact abrading of the end area of the wall blank in the above-noted prior art device can be realized only with great technical difficulties, especially as the overall wall thickness of the container is already very thin. Additionally, the container, which results after the winding operation and the insertion of the bottom, is not sufficiently rigid to resist denting. Therebeyond, the problem exists that when the grinding dust is not adequately removed, resulting in residues thereof which remain in the container, there is concern for hygienic reasons.